<script setup>
import { ref, onMounted, onBeforeUnmount, computed } from "vue";

// 定义响应式数据
const listItems = Array(5);
const products = ref([
  { name: "name", price: 10, image: "", isChecked: false },
  { name: "name", price: 20, image: "", isChecked: false },
  { name: "name", price: 15, image: "", isChecked: false },
  { name: "name", price: 8, image: "", isChecked: false },
  { name: "name", price: 25, image: "", isChecked: false },
  { name: "name", price: 12, image: "", isChecked: false },
  { name: "name", price: 12, image: "", isChecked: false },
]);
const currentPage = ref(1);
const itemsPerPage = 6;
const totalPages = ref(1);
const pageNumbers = ref([]);
const totalPrice = ref(0);
const isSticky = ref(false);
const searchKeyword = ref("");

// 计算属性：过滤商品
const filteredProducts = computed(() => {
  if (!searchKeyword.value) {
    return products.value;
  }
  return products.value.filter((product) =>
    product.name.toLowerCase().includes(searchKeyword.value.toLowerCase())
  );
});

// 计算属性：获取当前页的商品
const currentPageProducts = computed(() => {
  const startIndex = (currentPage.value - 1) * itemsPerPage;
  const endIndex = startIndex + itemsPerPage;
  return filteredProducts.value.slice(startIndex, endIndex);
});

// 滚动事件处理函数
const handleScroll = () => {
  if (window.pageYOffset > 0) {
    isSticky.value = true;
  } else {
    isSticky.value = false;
  }
};

// 计算总价函数
const calculateTotal = () => {
  totalPrice.value = currentPageProducts.value
    .filter((product) => product.isChecked)
    .reduce((sum, product) => sum + product.price, 0);
};

// 删除商品函数
const deleteProduct = (index) => {
  const currentProducts = currentPageProducts.value;
  const productIndex = filteredProducts.value.findIndex(
    (p) => p === currentProducts[index]
  );
  filteredProducts.value.splice(productIndex, 1);
  updatePageNumbers();
};
// 上一页函数
const prevPage = () => {
  if (currentPage.value > 1) {
    currentPage.value--;
  }
  updatePageNumbers();
};

// 下一页函数
const nextPage = () => {
  if (currentPage.value < totalPages.value) {
    currentPage.value++;
  }
  updatePageNumbers();
};

// 跳转到指定页函数
const goToPage = (page) => {
  currentPage.value = page;
  updatePageNumbers();
};

// 更新页码函数
const updatePageNumbers = () => {
  totalPages.value = Math.ceil(filteredProducts.value.length / itemsPerPage);
  pageNumbers.value = Array.from({ length: totalPages.value }, (_, i) => i + 1);
};

// 全选商品函数
const selectAllProducts = () => {
  const allChecked = currentPageProducts.value.every(
    (product) => product.isChecked
  );
  currentPageProducts.value.forEach((product) => {
    product.isChecked = !allChecked;
  });
  calculateTotal(); // 全选/取消全选后重新计算总价
};

// 挂载时绑定滚动事件并更新页码
onMounted(() => {
  window.addEventListener("scroll", handleScroll);
  updatePageNumbers();
});

// 卸载前移除滚动事件
onBeforeUnmount(() => {
  window.removeEventListener("scroll", handleScroll);
});
</script>
<template>
  <div>
    <nav class="top-navbar" :class="{ fixed: isSticky }">
      <div class="back">
        <button>&lt;</button>
      </div>
      <div class="nav-right">
        <a href="#" class="nav-link">首页</a>
        <a href="#" class="nav-link">个人中心</a>
        <a href="#" class="nav-link">购物车</a>
        <a href="#" class="nav-link">收藏夹</a>
        <a href="#" class="nav-link">帮助中心</a>
        <button class="sign-in-button">Sign in</button>
        <button class="register-button">Register</button>
      </div>
    </nav>
    <div class="shopping-cart">
      <div class="left-panel">
        <h2>总计</h2>
        <ul class="left-list">
          <li v-for="(item, index) in products" :key="index">
            {{ item.name }}
          </li>
        </ul>
        <button class="total-button" @click="calculateTotal">计算</button>
        <span class="total-price">¥{{ totalPrice }}</span>
      </div>
      <div class="right-panel">
        <div class="filter-search">
          <button class="all-button" @click="selectAllProducts">all</button>
          <input
            type="text"
            placeholder="search"
            class="search-input"
            v-model="searchKeyword"
          />
          <button class="search-icon"><i class="fas fa-search">🔍</i></button>
        </div>
        <div class="product-list">
          <!-- 商品 -->
          <div
            class="product-item"
            v-for="(product, index) in currentPageProducts"
            :key="index"
          >
            <input type="checkbox" v-model="product.isChecked" />
            <img :src="product.image" alt="product" class="product-image" />
            <div class="product-info">
              <span class="product-name">{{ product.name }}</span>
              <span class="product-price">¥{{ product.price }}</span>
              <button class="delete-button" @click="deleteProduct(index)">
                delete
              </button>
            </div>
          </div>
        </div>
        <!-- 商品 -->
        <div class="pagep">
          <div class="pagination">
            <button class="prev-button" @click="prevPage">上一页</button>
            <span>{{ currentPage }}</span>
            <button class="next-button" @click="nextPage">下一页</button>
          </div>
        </div>
      </div>
    </div>
  </div>
</template>



<style scoped>
* {
  margin: 0 auto;
  padding: 0;
}
#app {
  width: 100%;
  height: auto;
  margin: 0;
  padding-top: 0;
  font-family: Avenir, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-align: center;
  color: #2c3e50;
}
.top-navbar {
  display: flex;
  justify-content: space-between;
  gap: 20vh;
  background-color: #f4f4f4;
  padding: 10px;
  position: relative;
  z-index: 100px;
  transition: all 0.3s ease;
}
.back {
  display: flex;
  justify-content: start;
}
.nav-right {
  display: flex;
  align-content: flex-end;
}
.fixed {
  position: sticky;
  top: 0;
  width: 100%;
  background-color: #f4f4f4;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}
.nav-link {
  margin-right: 20px;
  text-decoration: none;
  color: #333;
}
.sign-in-button,
.register-button {
  background-color: #333;
  color: white;
  border: none;
  padding: 5px 10px;
  cursor: pointer;
}
.shopping-cart {
  margin-top: 50px;
  display: flex;
  width: 100%;
  height: 100vh;
}
.left-panel {
  width: 300px;
  padding: 20px;
  background-color: #f4f4f4;
}
.right-panel {
  flex: 1;
  padding: 20px;
  background-color: #fff;
}
.pagep {
  position: relative;
  bottom: -100px;
}
.filter-search {
  display: flex;
  align-items: center;
  margin-bottom: 20px;
}
.all-button {
  margin-right: 10px;
  padding: 5px 10px;
  background-color: #333;
  color: white;
  border: none;
  cursor: pointer;
}
.search-input {
  flex: 1;
  padding: 5px;
}
.search-icon {
  padding: 5px 10px;
  background-color: #fff;
  border: 1px solid #ccc;
  cursor: pointer;
}
.product-list {
  display: flex;
  flex-direction: column;
}
.product-item {
  width: calc(100% - 20px);
  margin-bottom: 20px;
  border: 1px solid #ccc;
  padding: 10px;
  box-sizing: border-box;
  display: flex;
  align-items: center;
}
.product-image {
  width: 100%;
  height: auto;
}
.product-info {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex: 1;
  margin-left: 10px;
}
.delete-button {
  background-color: #333;
  color: white;
  border: none;
  padding: 5px 10px;
  cursor: pointer;
}
.pagination {
  position: absolute;
  bottom: 40px;
  right: 40%;
  display: flex;
  justify-content: center;
  gap: 1vh;
  margin-top: 20px;
}
.prev-button,
.next-button {
  padding: 5px 10px;
  background-color: #ccc;
  border: none;
  cursor: pointer;
}
.active-page {
  background-color: #333;
  color: white;
  padding: 5px 10px;
  margin: 0 5px;
  cursor: pointer;
}
.total-button {
  width: 100%;
  padding: 10px;
  background-color: #333;
  color: white;
  border: none;
  cursor: pointer;
  margin-top: 20px;
}

.left-list {
  list-style: none;
}
</style>
